| 摘要 |
PURPOSE:To provide a back light constituted so that the rising of luminous flux is improved and the luminance thereof is enhanced when it is used in a low temperature state and light radiated from a lamp is made to proceed toward a light transmission plate without being interrupted, and a liquid crystal display device using it. CONSTITUTION:The back light is provided with the planar light transmission plate 3 transmitting the light, the low-voltage electric discharge lamp 4 provided to be faced to the end surface of the plate 3, a lamp cover 7 guiding the light radiated from the lamp 4 to the inside of the plate 3 from the end surface thereof and a heater 10 provided on the outside surface of the cover 7. Since the lamp is heated by the heater 10, the temperature thereof is raised even in low-temperature atomosphere. Then, the rising of the luminous flux is improved and the luminance thereof is enhanced. Besides, since the outside surf ace of the cover 7 is provided with the heater 10, the light radiated from the lamp is not absorbed or interrupted, and the luminance of the plate 3 is enhanced. |
